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The modern genre of werewolf books, TV series and movies are in complete agreement with the 1941 Hollywood classic film The Wolf Man. Yep, if you are so inclined, the full Moon will turn you into a lunatic werewolf.

Indeed, that rather antiquated word 'lunacy' comes from Luna, who was the Roman Goddess of the Moon. One definition of lunacy is "intermittent insanity once believed to be related to phases of the moon".

This belief goes back a long way. The Roman scientist and military commander, Pliny the Elder, said that because the full Moon causes a very heavy nocturnal dew, it must also make the brain become "unnaturally moist". That was how, he claimed, the Moon caused both epilepsy and lunacy. He was wrong.

Even so, the belief is still common today. One survey in the USA found that about 40 per cent of the general population, and 80 per cent of mental health professionals, believe that the phase of the Moon affects human behaviour.

And yet, 99+ per cent of the evidence says that the Moon has no effect on human behaviour.

The Moon takes just under a month to run from full (brightest), to half-full, to new (darkest), to half-full and back to full again.

But it's the full Moon that is claimed to be related to a huge list of human misery, including accidents, alcoholism, anxiety, assaults, calls to crisis telephone numbers, casino activity, depression, domestic violence, drug overdoses and, of course, emergency-room visits.

Over the last half-century, thousands of studies have looked at the Moon's effect upon the behaviours in my little list. Occasionally, one of these studies will show a correlation with the fullness of the Moon. But then the more thorough follow-up studies show absolutely no correlation at all.

Mind you, that's what the scientific literature shows. That's quite different from what will appear in your local newspaper, or on your TV. After all, the journalists have a deadline to keep, and a story to manufacture, and they won't let the facts get in the way.

But there is a place for the lunar effect. You see, in the academic papers, the people studied are in modern societies, and have artificial light at night.

But before artificial lighting, people stayed up later on the full Moon. After all, if the full Moon is hanging in the sky, it's 250-times brighter than if there's no moonlight at all.

So, even today, in so-called primitive societies that don't have artificial lighting at night, a full Moon is the occasion for a party, revelry and a general good time. The fabric of their society is organised around the full Moon. So if there are more people around, then obviously there will be more frequent mishaps.

Definitely, more people around does mean more human activity.

But in our modern technological society, does the Moon make people go mad, does it increase numbers at hospital emergency rooms or does it increase self-harm? Nope, the hard evidence says it doesn't happen.

One theory that's been put forward to explain this non-existent lunar-lunacy effect is that the Moon has a huge effect on the tides, which are made of water. Therefore, runs the biological-tides theory, because we are mostly water, the Moon must have an effect on us.

This so-called 'theory' is wrong in a few ways.

First, the Moon-tides thing happens because the oceans are large, and made of a liquid. They would still happen if the liquid was freezing liquid hydrogen, room temperature mercury, or hot liquid iron. It doesn't have to be water.

Second, tides happen only over large expanses, not within the small dimensions of a human body.

Third, the ocean tides still happen if the Moon is full, new or half-full. The Moon still has a gravitational effect even if the Sun doesn't fully light it up for us.

A better theory to explain it all is selective recall. It's a busy night, and you look out the window to see that rare animal, the full Moon. You put two and two together to make five, and assume that the full Moon made your night busy.

This belief that the full Moon massively affects human behaviour is a cultural fossil. It's a memory of the effect that we would party on a full Moon, way back when we had no artificial light.

lloyd knight :

xander :

02 Apr 2012 11:56:45am

Most hunting from animals such as lions and other big cats occurs in the extra- dark - extra long window that occurs just after sundown and immediately before a full moon rises. This is the best time for a violent predator to hunt, man or beast, because its the longest darkest period of the month - offering the best shroud possible... before a full moon rises to illuminate the carnage... There is reason in all the blood/moon/beast/violence connections after all. Scientific and logical hunting windows of opportunity.

Norm :

04 Apr 2012 1:27:31pm

Hmm... The basis of all Science is observation. If you check next full moon, you will notice there is no dark between sunset and moonrise. If you are on flat land, you will see both on opposite horizons at once. even if not, it will still be dusk.

keiran harris :

janelle :

29 Mar 2012 11:13:33am

I agree with the policeman's wife. Mentally ill patients do tend to be more maniac during this period. Want science evidence? see the paper "Lunacy revisited. The influence of the moon on mental health and quality of life.J Psychosoc Nurs Ment Health Serv. 2000 May ;38(5):28-35". Which showed significant change at the time of the full moon in subjects with a diagnosis of schizophrenia (n = 56), where deterioration was observed in three areas of psychopathology and one area of quality of life.

Grilled Bear :

Dr Chloe :

29 Mar 2012 8:32:31pm

There is definitely evidence that health problems in women worsen just before the menstral peiod. Also women are more likely to have accidents and commit crimes at this time.The less urban the environment the more likely a woman is to cycle with the moon.

the digger :

immeyouareyou :

Karen :

30 Mar 2012 4:59:05pm

Perhaps there is more to the moon than science can explain. My mother worked in a hospital for the mentally ill. She said the staff dreaded the full moon because the patients became agitated and more difficult to manage.

Nick :

Unbeliever :

There was a lack of evidence that thalidomide was harmfull for a long time, until someone paid for the appropriate studies.

A lack of evidence is not always conclusive proof one way or the other, it is just a lack of knowledge.

Observational evidence from the police forces (world wide) would indicate some degree of impact on human behaviour, which is why every police officer knows to dread the full moon (because on average people behave different then) and why more officers are on the beat on a full moon.

xander :

02 Apr 2012 11:49:55am

what is NOT puff is the fact that the linking of violence and misdemeanor to a full moon is quite sound.When a full moon occurs there is the longest period of time after sundown until the moon rises - in this time it is the darkest period of night all month. looking at predatory attacks from creatures ranging from lions to humans(look it up I forget no's)there is a remarkable window of carnage when a predator is hidden in the deepest of darkenss for the longest period of time - all month - this is when an astounding amount and percentage of predatory attacks takes place -logically shrouded in darkness. This also helps account for the visual impairment that assists accidents in developing. Then this period is illuminated at its best when the full moon eventually rises - shining light upon the violence and as stated, allowing for more marked and well lit nocturnal activity after the predators window of darkness. Fair reasons for such documented activity.

Norm :

Tom Draper :

03 Apr 2012 8:42:41pm

I am a very clear headed and intelligent person, an engineer by profession. I am absolutely convinced beyond a doubt that there is a direct connection between the full moon and tinnitus. Friday is full moon. Tonight the sky is as devoid of haze as it will ever be. I went outside and there it was, directly overhead, as I told my friends. They find it hard to believe. My ears are giving me hell, pulsating and ringing constantly and only in the last hour or so. It's only on these absolutely clear nights that I have ear trouble when the moon is directly overhead. There has to be a scientific reason. I'm simply not stupid. I have experienced the condition dozens of times and the nights were always clear and the moon directly overhead here in Noosa. I've been here 20 years.

Grilled Bear :

Kerry :

09 Apr 2012 11:00:50pm

I too, am affected by the moon. I have not been on on any contraception for over ten years now, and so my menstrual cycle is not disrupted. I am a rationalist, so I would like a scientific explaination why I cycle with the moon. I travel every 2 years over to England from Australia and my cycle is disrupted, but then slowly starts cyclying with the moon again after around 3 to 4 months. Why?

Solon 6 :

jim :

23 Apr 2012 10:25:42pm

It is the week up to the full moon that is most productive with fishing.Same with crabbing, then nothing. As with night hunting in centuries past,there may be some bodily activity not detected yet because of instinct patterning. Humans would maybe get more restless or an anxiety state of contemplation. One thing i've noticed when the moon is out that i get a sore neck.

immeyouareyou :

04 May 2012 5:59:48pm

I would like Dr. Skeptic to explain why I can ALWAYS and I means always tell when the moon is full because of my urge to fight and be out at night. I don't check the calender,keep tract in any way; I get the urges and I check and there it is every time, a full moon.

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